.TH std::chrono::weekday::weekday 3 "2024.06.10" "http://cppreference.com" "C++ Standard Libary"
.SH NAME
std::chrono::weekday::weekday \- std::chrono::weekday::weekday

.SH Synopsis
   weekday() = default;                                               \fB(1)\fP \fI(since C++20)\fP
   constexpr explicit weekday( unsigned wd ) noexcept;                \fB(2)\fP \fI(since C++20)\fP
   constexpr weekday( const std::chrono::sys_days& sd ) noexcept;     \fB(3)\fP \fI(since C++20)\fP
   constexpr explicit weekday( const std::chrono::local_days& ld )    \fB(4)\fP \fI(since C++20)\fP
   noexcept;

   Constructs a weekday object.

   1) Default constructor leaves the weekday value uninitialized.
   2) Constructs a weekday object holding the weekday value wd. If wd == 7, the value
   held is 0. If wd > 255, the value held is unspecified.
   3) Constructs a weekday object representing the day of the week sd corresponds to.
   This constructor defines an implicit conversion from std::chrono::sys_days to
   weekday.
   4) Constructs a weekday object representing the day of the week ld corresponds to,
   as if by weekday(std::chrono::sys_days(ld.time_since_epoch())).

.SH Parameters

   wd - a weekday value
   sd - a system days object
   ld - a local days object

.SH Example


// Run this code

 #include <chrono>
 #include <iomanip>
 #include <iostream>

 int main()
 {
     constexpr std::chrono::weekday friday{5}; // uses overload (2)
     static_assert(friday == std::chrono::Friday);

     for (int y{2020}; y <= 2023; ++y)
     {
         const std::chrono::year cur_year{y};
         for (int cur_month{1}; cur_month != 13; ++cur_month)
         {
             const std::chrono::year_month_day ymd{cur_year/cur_month/13};
             const std::chrono::weekday cur_weekday{std::chrono::sys_days(ymd)}; // (3)
             if (cur_weekday == friday)
                 std::cout << ymd << " is " << friday << '\\n';
         }
     }
 }

.SH Output:

 2020-03-13 is Fri
 2020-11-13 is Fri
 2021-08-13 is Fri
 2022-05-13 is Fri
 2023-01-13 is Fri
 2023-10-13 is Fri
